Towards efficient growth of transparent Mo oxides by PLD

Spring Meeting 2019. International Conference on Advanced Materials, Acropolis Congress Centre, Nice, France, May 27-31 2019Transparent conductive oxides (TCO¿s) have been widely used as transparent electrodes for solar cells and mobile display panels because they present unique properties of coexistence of visible transparency and electronic conduction. One of the more used and extended is the Indium Tin Oxide (ITO), however Indium is scarce and this has motivated the investigation of new TCO¿s based on more abundant elements and with capability of tunable properties. In this context, molybdenum oxides are semiconductors with different optical and electronic properties depending on their stoichiometry: MoO3 presents transparency showing a wide bandgap (>3 eV), whereas MoO2 is a semimetal [1]. Upon introducing oxygen defects in MoO3, gap states can be generated effectively changing its response and allowing to the tunability of the material properties. In this contribution we will show the strategies that we are developing to deposit MoOx by PLD. We achieve the successful growth of MoOx films from a MoO3 target by using different starting background vacuum conditions. The films stoichiometry and therefore their optical response is further tuned by post-deposition annealing in air in up to 400ºC. We have studied the evolution of the dielectric function as a function of the deposition and post-annealing conditions in order to obtain films with optimized transparency